Give one example of an element and one compound.

Can someone help me with this pls

At 450 mm hg a gas has a volume of 760 l, what is its volume at standard pressure

The twister and runaway train are two coasters at the same amusement park. both coasters start at the same height. the coaster for the twister is twice the mass of the coaster for the runaway train. which roller coaster has greater gravitational potential energy at the start of the ride?

Can someone me with 6 to 10 plz this is for masteries test.